I’ve been looking for a better way to review LeetCode problems without sitting down and solving the same ones from scratch every time. Flashcards seem like a pretty good fit: see the problem, try to recall the pattern, and check whether you actually remember the approach.

Here are three resources I found worth sharing. The first two are the standouts; the third is a handy option for reviewing on your phone.

1. LeetCode + NeetCode Anki

ayorgo/leetcode-neetcode-anki on GitHub

This is a great starting point if you’re already using Anki or want to get into spaced repetition. Instead of relying on the feeling that you sort of remember a problem, you can revisit it on a schedule and see whether you can recall the solution strategy.

I especially like the NeetCode angle because it fits nicely with studying by patterns rather than randomly grinding problems.

2. LeetCode Flashcards + Big-O Game

kaziridwan/leetcode-flashcards on GitHub

This one is probably the most fun of the three. Alongside flashcard-style problem review, it has a Big-O game, so you can practice recognizing complexity instead of just reading through solutions.

That’s useful because knowing how to write a solution and being able to explain why it’s efficient are two different skills. A little game-like practice is a nice change from another hour staring at an editor.

3. LeetCard — for quick mobile reviews

leetcard.dev

LeetCard is my bonus recommendation when you want something easy to pull up on a phone. It’s a mobile-friendly web app, so there’s no need to make time for a full coding session just to review a few problems.

It’s especially appealing for those in-between moments when you have five minutes to spare.

Flashcards aren’t a replacement for coding

I wouldn’t use any of these as a substitute for actually solving problems. It’s easy to recognize an answer on a card and mistake that for being able to write the code from a blank editor.

But as a supplement? I think they’re excellent. If I can remember which pattern to use, the key edge cases, and the time complexity before I start typing, that’s already a big win.

My picks: start with the Anki deck for consistent review, try the flashcards and Big-O game for a more interactive approach, and keep LeetCard bookmarked for your phone.